|Jmol-3D images||Image 1|
|Molar mass||172.18 g mol−1|
|Appearance||Bright yellow crystals|
304.5 °C @ 760mmHg
|Solubility in water||Insoluble|
|Flash point||113.8 °C|
|LD50||0.5 g/kg (oral, mouse)|
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Menadione is a synthetic chemical compound sometimes used as a nutritional supplement because of its vitamin K activity. It is an analog of 1,4-naphthoquinone with a methyl group in the 2-position.
It is sometimes called vitamin K3, although derivatives of naphthoquinone without the side chain in the 3-position cannot exert all the functions of the K vitamins. Menadione is a vitamin precursor of K2 which utilizes alkylation to yield menaquinones (MK-n, n=1-13; K2 vitamers), and hence, is better classified as a provitamin.
It is also known as "menaphthone".
Despite the fact that it can serve as a precursor to various types of vitamin K, menadione is generally not used as a nutritional supplement in economically developed countries. Menadione for human use at pharmaceutical strength is available in some countries with large lower income populations. Large doses of menadione have been reported to cause adverse outcomes including hemolytic anemia due to G6PD deficiency, neonatal brain or liver damage, or neonatal death in some rare cases. In the United States, menadione supplements are banned by the U.S. Food and Drug Administration (FDA) because of their potential toxicity in human use.
Low dose menadione is still used as an inexpensive micronutrient for livestock in many countries. Forms of menadione are also included in some pet foods in developed countries as a source of vitamin K. These doses have yielded no reported cases of toxicity from menadione in livestock or pets.
It is used in the treatment of Hypoprothrombinemia outside of the United States.
Experimental research 
A menadione topical lotion was recently developed to reduce epidermal growth factor receptor inhibitor related side effects, by the prevention of skin toxicities that result from inhibition of protein kinases by drugs such as erlotinib (Tarceva) and cetuximab (Erbitux).
- The Merck Index, 11th Edition, 5714
- Castro FA, Mariani D, Panek AD, Eleutherio EC, Pereira MD (2008). "Cytotoxicity Mechanism of Two Naphthoquinones (Menadione and Plumbagin) in Saccharomyces cerevisiae". In Fox, Debbie. PLoS ONE 3 (12): e3999. doi:10.1371/journal.pone.0003999. PMC 2600608. PMID 19098979.
- Scott GK, Atsriku C, Kaminker P, et al (September 2005). "Vitamin K3 (menadione)-induced oncosis associated with keratin 8 phosphorylation and histone H3 arylation". Mol. Pharmacol. 68 (3): 606–15. doi:10.1124/mol.105.013474. PMID 15939799.
- "Vitamin K". Retrieved 2009-03-18.
- James M. Jamison, Jacques Gilloteaux, Henryk S. Taper and Jack L. Summers (2001). "Evaluation of the In Vitro and In Vivo Antitumor Activities of Vitamin C and K-3 Combinations against Human Prostate Cancer". J. Nutr. 131 (1): 158S–160S. PMID 11208954.
- Tareen B, Summers JL, Jamison JM, Neal DR, McGuire K, Gerson L, Diokno A (2008). "A 12 Week, Open Label, Phase I/IIa Study Using Apatone® for the Treatment of Prostate Cancer Patients Who Have Failed Standard Therapy". Int J Med Sci 5 (2): 62–67. PMC 2288789. PMID 18392145.
- R. Perez-Soler, Y. Ling, Y. Zou, S.R. Deitcher (2008). "Local Rescue of Skin Toxicities Secondary to Kinase Inhibitor (KI) Therapy with Topical Menadione". Annals of Oncology.
- Tianhong Li and Roman Perez-Soler (2009). "Skin toxicities associated with epidermal growth factor receptor inhibitors". Targeted Oncology 4 (2): 107–119. doi:10.1007/s11523-009-0114-0. PMID 19452131.